To make the dressing mayonnaise, parmesan cheese, lemon juice, vinegar, sugar, parsley, garlic powder, salt, black pepper, and red pepper to a blender. While blending, slowly drizzle in the olive oil through the opening in the blender lid. Blend until ingredients are combined and thicken ever so slightly. Transfer dressing to a sealable glass container (like a mason jar) until ready to serve if not serving immediately.

To assemble the salad, add the lettuce to a large bowl. Toss with the Italian dressing now if serving immediately. You don't have to dress the salad though, you can just pour over individual servings if desired.

Top the lettuce with the cherry tomatoes, black olives, onion slices and pepperoncini. Top with extra freshly grated parmesan cheese if desired. Serve immediately or cover and refrigerate until ready to serve. Do not add the salad dressing until ready to serve.